Understanding Naegleria fowleri: From Ecology to Infection

Abstract

Naegleria fowleri, more commonly known as the “brain-eating amoeba,” is a unicellular protozoan found in warm freshwater, artificial water systems, soil, and sediments. Various ecological factors—such as temperature, light exposure, and environmental disturbances—affect N. fowleri’s distribution and abundance. Although it is a single-celled organism, N. fowleri is a highly aggressive and dangerous facultative parasite capable of causing primary amebic meningoencephalitis (PAM), a rapidly fatal brain infection. Infection occurs when contaminated water enters the nose, allowing the amoeba to travel to the brain. Once in the brain, it causes inflammation and tissue destruction. Despite the use of drugs, the fatality rate remains extremely high, with very few survivors among reported cases. Timely clinical diagnosis is critical, but it is often difficult due to the nonspecific nature of early symptoms. This paper will review the biology, ecological influences, immune response, and diagnosis of N. fowleri, while also emphasizing the importance of prevention and public awareness in mitigating the risk of PAM.